Automatic remote control apparatus

ABSTRACT

Hydraulic control apparatus for automatic remote control of a hydraulic actuating ram. The apparatus has a double-acting slave cylinder connectable hydraulically to an actuating ram, and a double-acting master cylinder the piston of which is mechanically connected to the piston of the slave cylinder, the master cylinder being operable by hydraulic pressure supplied via a pilot-operated valve arranged automatically to reverse the stroke of the master ram at limits set according to the desired stroke of the actuating ram. The control apparatus may be used for controlling actuating rams which effect reciprocating pivotal movement about one or more axes of a water jet monitor.

United States Patent [1 1 Luke [ Sept. 17, 1974 [5 1 AUTOMATIC REMOTECONTROL APPARATUS William George Luke, Cornwall, England [22] Filed:Apr. 9, 1973 [21] Appl. No.: 349,463

[75] Inventor:

[30] Foreign Application Priority Data 3,583,637 6/1971 Miscovich239/587 Primary ExaminerLloyd L. King Attorney, Agent, orFirm-Armstrong, Nikaido &

Wegner [5 7 ABSTRACT Hydraulic control apparatus for automatic remotecontrol of a hydraulic actuating ram. The apparatus has a double-actingslave cylinder connectable hydraulically to an actuating ram, and adouble-acting master cylinder the piston of which is mechanicallyconnected to the piston of the slave cylinder, the mas- Apr. 14, 1972Great Britain 17418/72 ter ylinder being operable by hydraulic pressuresupplied via a pilot-operated valve arranged automatically [52] US. Cl.239/587 to rever e the troke of the master mm at limits set ac- [51]Int. Cl B05b 15/08 o ding to the desired stroke of the actuating ram.[58] Fleld of Search 239/587, 227 The control apparatus may be used forcontrolling actuating rams which effect reciprocating pivotal move- [5Re e e ce Clted ment about one or more axes of a water jet monitor.

UNITED STATES PATENTS 7 Claims, 5 Drawing Figures 3,575,351 4/]971Warren 239/587 w o 1' g p l l 7 Q, I l ,b

PAIENIE SEP 1 H974 SHEET 2 OF 5 1 AUTOMATIC REMOTE CONTROL APPARATUSBACKGROUND OF THE INVENTION This invention relates to hydraulic controlapparatus for automatic remote control of a hydraulic actuating ram, andis particularly, though not exclusively, concerned with remote controlof movement of the nozzle of a high-velocity water jet monitor.

In a number of mining industries, for example the clay industry, ahigh-pressure water jet, from the nozzle of a water jet monitor, is usedto wash minerals from the earth. This washing'process has been improvedin recent years by increasing the velocity of the water jet and bydirecting the water jet more effectively at the area to be washed,washing being carried out by traversing the jet of water continuallyback and forth over a selected area of the earth. Because of the highpressure of water involved and the time required to wash a particulararea effectively it is desirable to employ remote control of themovement of the nozzle so that the operator can supervise the monitorfrom a safe distance and avoid repetitive manual control over longperiods. One method of traversing the jet back and forth is by adaptingthe nozzle of the monitor to be movable, for example by pivoting, bymeans of a hydraulic actuating ram or rams.

SUMMARY OF THE INVENTION According to one aspect of the presentinvention there is provided hydraulic control apparatus for automaticremote control of a hydraulic actuating ram, comprising a firstdouble-acting cylinder, referred to as a slave cylinder, which can beconnected hydraulically for driving the actuating ram, and a seconddoubleacting cylinder, referred to as a master cylinder, the piston ofthe slave cylinder being mechanically connected to the piston of themaster cylinder whereby reciprocating movement of the master pistoncauses corresponding reciprocating movement of the slave piston, themaster cylinder being operable by hydraulic pressure under the controlof a pilot-operated hydraulic valve which is arranged automatically toreverse the direction of movement of the master ram in response to pilotmeans actuable by limit switch means arranged for determining thedesired length of stroke of the actuating ram.

The pilot means may comprise two hydraulic pilot valves arranged to beactuated at completion of a preset stroke of the master or slave ramsfor example by latches which are adjustable so that their positiondetermines the length of stroke of the master ram.

The control apparatus may include a manuallyoperable hydraulic valve forcontrolling the hydraulic actuating ram, the manual valve, whenoperated, overriding the automatic control of the master and slavecylinders.

In one embodiment of the invention there is provided a water jet monitorincluding a nozzle mounted for pivotal movement in at least one plane,the pivotal movement being effected by means of a hydraulic actuatingram which is arranged to be controlled automatically by hydrauliccontrol apparatus according to the invention. Conveniently a flowcontrol valve is connected between the slave cylinder and the actuatingram for controlling the rate of movement of the actuating ram, therebycontrolling the rate of pivotal movement of the monitor nozzle.

In practice, it is often desirable to control the movement of a monitornozzle so that the water jet traverses an area to be washed in ahorizontal direction, or a vertical direction, or in both horizontal andvertical directions simultaneously. In a preferred embodiment of theinvention therefore, a water jet monitor is provided in which the nozzleis mounted for pivotal movement in two mutually perpendicular planes, afirst actuating ram being provided for effecting movement of the nozzlein one plane and a second actuating ram being provided for effectingmovement of the nozzle in the other plane, each actuating ram beingarranged to be remotely controlled automatically by hydraulic controlapparatus according to the invention. In this way the control apparatusmay be set so as to control automatically the movement of the monitornozzle for a large variety of different washing programmes, by selectingthe stroke and speed of movement of each actuating ram, for example, inboth the vertical and horizontal directions.

The hydraulic pressure for each master cylinder of the control apparatusmay be supplied from a pump driven by an electric motor. This does havethe disadvantage, however, of requiring installation of electrical powerlines which are both costly, awkward to move when the monitor is to bemoved to a new location, and constitute a hazard in a mining pit whereheavy vehicles are usually operated.

According to a further aspect of the invention therefore, there isprovided a high velocity water jet monitor wherein the hydraulicpressure for operating control apparatus of the water jet monitor issupplied by a pump which is coupled to a hydraulic motor driven by meansof water pressure derived from the supply of water to the nozzle of themonitor. The power unit is thus self-contained and therefore avoids thehazards mentioned above, and moreover it can easily be moved to a newlocation together with the control apparatus and the monitor for washingdifferent areas of the mining pit. Conveniently the hydraulic motorcomprises a Pelton wheel.

BRIEF DESCRIPTION OF THE DRAWINGS The invention may be carried intopractice in various ways, but one specific embodiment will now bedescribed, by way of example, with reference to the accompanyingdrawings, in which:

FIG. 1 is a view of a high-velocity water jet monitor having a nozzlewhich can be pivoted horizontally and vertically;

FIG. 2 is a diagrammatic layout showing the arrangement of a monitortogether with its remote control unit and a hydraulic power unit;

FIG. 3 is a circuit diagram showing the hydraulic circuit of the controlapparatus according to the invention;

FIG. 4 is a view of the hydraulic power unit which supplies oil underpressure to the control apparatus, and

FIG. 5 is a perspective view of the control unit, showing the controls.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A high-velocity waterjet monitor such as is used in the china-clay industry for washingchina-clay from the earth is shown generally in FIG. 1. The monitor hasa nozzle 1 from which a high-velocity jet of water issues when themonitor is in use, the jet being directed at an area of earth where thechina-clay is to be washed out. The water is supplied to the nozzleunder high pressure through a supply pipe 2 which is secured to a base 3and which is further arranged in the form of a loop or coil 4 forcountering the reaction thrust of the jet, the supply pipe terminatingat the nozzle 1. The supply pipe, above the base, includes a firstbearing 5 for pivoting the nozzle 1 about a vertical axis, and a secondbearing 6 situated at the beginning of the loop 4 for pivoting thenozzle about a horizontal axis. Pivoting movement of the nozzle iseffected by means of hydraulically-operated actuating rams 7 and 8connected respectively to the bearings 5 and 6 so that the nozzle 1, andhence the jet of water, can be moved in a horizontal or verticaldirection or both. The actuating rams 7 and 8 which are double-actingare operated by oil under pressure fed via flexible conduits 10, 11 and13, 13 from a control unit as will be explained. The flexible conduitsare attached to the cylinders by self-sealing releasable couplings.

The general layout of the monitor with its control unit is showndiagrammatically in FIG. 2. This figure shows the monitor, indicatedgenerally at 15, the remote control apparatus 20 and the hydraulic powerunit 50 for supplying oil under pressure to the control apparatus. Asshown, the four conduits 10, 11 and 12, 13 connect the actuating rams 7and 8 of the monitor to the control apparatus, oil being suppliedthrough these conduits to operate the actuating rams 7 and 8 for movingthe nozzle. The conduits 10, 11 and 12, 13may be made of any suitablelength, normally 100 ft., so that the control apparatus 20 can belocated at a safe working distance from the monitor. This feature isrequired since the high-velocity jet of water from the nozzle 1 causesrocks and mud to be thrown considerable distances owing to the impactwith which the water hits the earth.

The control apparatus 20 and its hydraulic power unit are convenientlyhoused in a hut 60 which further protects the operator and makesoperating possible in bad weather conditions.

Using the present invention it is possible for the operator to set aprogramme on the control apparatus so that operation of the actuatingrams 7 and 8 will continue automatically, the programme being selectedby the operator according to the way in which the area is to be washedby the water jet. The control circuit by which this is achieved is shownin FIG. 3. This diagram shows the hydraulic circuit for operating one ofthe actuating rams, for example ram 7 which produces horizontal movementof the nozzle. The circuit for operating the other ram 8 is not shownbut is identical in all respects.

The double-acting actuating ram 7 which has oil conduits l0 and 11connected to opposite ends of its cylinder can be operated in two ways,either manually through the control lever 28 of a manual control valve23 or through the automatic circuit indicated generally at 24. Themanual valve is a directional, 3-position valve in which the valve spoolis spring-biassed to its centre closed position. Movement of the valvespool, for example to the left in FIG. 3, puts conduit in communicationwith an oil reservoir, and admits oil pressure through conduit 11 to thecylinder of the actuating ram 7, causing its ram to move outwardly.Conversely if the valve spool is moved to the right, oil pressure is fedto conduit 10 and conduit 11 is connected to the reservoir, so that theram of the actuating cylinder moves into the cylinder.

In the centre position of the valve 23, as shown in the Figure, theactuating cylinder 7 is hydraulically locked against movement.

For automatic operation, the actuating ram 7 is operated throughconduits 25 and 26 which communicate with conduits l1 and 10respectively. Conduit 25 has a needle valve 27 for controlling the rateof flow of oil from the automatic circuit 24 to the ram 7; if the needlevalve 27 is closed the ram 7 is isolated from the automatic control.

The control circuit 24 comprises basically two opposed double-actingrams, referred to as a slave cylinder 30 and a master cylinder 31, thepistons of which are directly coupled via a common piston rod 32 whichcarries a roller 33 for operating latches for reversing the direction atthe completion of a stroke of the master and slave rams, as will beexplained. The slave cylinder 30 is hydraulically connected to theactuating ram 7 via the conduits 25 and 26 which are connected toopposite ends by the slave cylinder 30, and the bore of the slavecylinder 30 is the same as that of the actuating ram 7 so thatreciprocating movement of the slave ram will cause exactly correspondingreciprocating linear movement of the actuating ram 7.

The master cylinder 31 is operated by oil pressure supplied from thehydraulic power unit 50 through conduits 35 and 36 under the control ofa pilot-operated, 3-position directional valve 37, the centre positionof the spool being a closed position. This reversing valve 37 isoperated by two pilot valves 38 and 39 which are operated by hydraulicpressure and actuated by associatedlatches 40 and 41 are arranged to bedepressed in turn by the roller 33 on the piston rod 32. Thus inoperation the master ram moves in one direction until the roller 33depresses one of the latches, say 40 which operates its associated pilotvalve 38, thereby changing over the main valve 37 to reverse thedirection of movement of the master ram. At the other end of the stroke,roller 33 will depress the latch 41, again to reverse the valve 37through the pilot valve 39. The reciprocating movement of the master ram31 produces corresponding reciprocating movement of the slave ram 30which in turn effects reciprocating movement of the actuating ram 7,thereby to oscillate the water jet horizontally.

One of the latches 41 is adjustable by means of a lever 43 which in aparticular construction can be set in any one of 13 positions, theposition of the latch determining the length of stroke of the master ram31 and therefore the length of stroke of the actuating ram 7.

As explained, the other actuating ram 8 for vertical movement of thenozzle is also controlled by a similar automatic control circuit.

FIG. 5 shows the control unit with the various controls: the controllever 28, the needle valve 27 and the stroke adjustment lever 43 forcontrolling the horizontal actuating ram 7; and corresponding controls28A, 27A and 43A for controlling the vertical actuating ram 8.

It will be appreciated therefore that by selecting the stroke and speedof actuation of each of the actuating rams 7 and 8, using the controls43, 43A and 27, 27A,

a wide range of automatic working programmes can be achieved. 'Once set,a programme will be followed continuously, until the operator changesthe controls. If the operator decides to move the jet to a new washingposition all that is necessary is to operate the relevant manual valve23, by means of its control lever 28 or 28A, which will then overridethe automatic control until the control lever is released, when thevalve spool will again return to its centre, locked position and thepreselected programme will re-commence.

In the embodiment described the slave cylinder has a maximum stroke of4" whereas the actuating ram 7 has a maximum stroke of Thus underautomatic control the range of movement is only a proportion of themaximum range; for example, the horizontal movement possible with a fullstroke of the actuating ram 7 may constitute a swing through 120 of thejet and under automatic control the maximum horizontal swing would be32; this provides a safe and effective range in practice. If the 15required to be directed at an area lying outside the 120, the nozzleassembly can be swung round to a new direction by means of a clamp 14,shown in FIG. 1.

A feature of the construction is the safety, in that, if by accident oneof the conduits is cut or torn away from its coupling, the oil underpressure which is normally fed to the actuating rams 7 and 8 will ventto atmosphere and movement of the nozzle will cease. Furthermore, sinceunder automatic operation the actuating rams 7 and 8 are in a closedhydraulic circuit with their associated slave cylinders, there is nodanger of drift outside the programmed range, provided there is noleakage of oil past those rams.

The hydraulic pressure for operating the master ram 31, and thecorresponding master ram of the vertical movement control circuit, issupplied by the power unit 50, as illustrated in FIG. 4. The oilpressure for the control apparatus is supplied from an oil pump 51 whichpumps oil from a reservoir 52 via a conduit 55 and thence under pressureto the control apparatus via a pressure supply conduit 56. An oil returnconduit 57 returns oil from the control apparatus to the reservoir 52.

The oil pump 51 is driven by a simple water-powered Pelton wheelarrangement 53 the Pelton wheel being driven by water under pressure fedthrough an inlet pipe 54 from the water supply pipe 2 which supplies thewash water to the nozzle. This provides a simple and efficientarrangement and it is found that 5 gallons of water per minute providesadequate power. It will be appreciated that this feature provides aselfcontained power unit obviating the expense and danger of electricalpower lines.

Furthermoresince the monitor, the control unit and the power unit areinterconnected by quick release couplings any one of these units may bereplaced quickly in event of trouble thereby avoiding loss of operatingtime and eliminating the need to service the units in difficultconditions.

In a further specific embodiment, not shown in the drawings, a singlecontrol circuit, as shown in FIG. 3, is used to control automaticallyeither a vertical movement actuating ram or a horizontal movementactuating ram but not both simultaneously. In this case the slave ram isconnected hydraulically to both vertical and horizontal actuating ramsvia a manual valve which can be operated to engage automatic control forwhichever actuating ram is selected. Since only one control circuit isused in this case the control apparatus is simpler and less expensive toinstall.

I claim:

1. A hydraulic monitor including a water jet nozzle mounted for pivotingmovement in at least one plane, the pivoting movement being effected bya hydraulic actuating ram which is arranged to be controlledautomatically by hydraulic control apparatus comprising a firstdouble-acting cylinder, referred to as a slave cylinder, which can beconnected hydraulically for driving the actuating ram, a seconddouble-acting ram, referred to as a master cylinder, a mechanicalconnection between the piston of the slave cylinder and the piston ofthe master cylinder, the connection being adapted to cause reciprocatingmovement of the slave piston corresponding to reciprocating movement ofthe master piston, a pilot-operated hydraulic valve adapted to controlthe hydraulic pressure supply to the master cylinder, the pilot-operatedhydraulic valve being arranged automatically to reverse the direction ofmovement of the master ram, pilot means adapted to control thepilot-operated hydraulic valve, and limit switch means adapted toactuate the pilot means and arranged for determining the desired lengthof stroke of the actuating ram.

2. A hydraulic monitor as claimed in claim 1, in which the hydraulicpressure for operating the master cylinder is supplied by a pump adaptedto be driven by a hydraulic motor driven by means of water pressurederived from the supply of water to the nozzle of the monitor.

3. A hydraulic monitor including a nozzle mounted for pivoting movementin two mutually perpendicular planes, a first actuating ram foreffecting movement of the nozzle in one plane and a second actuating ramfor effecting movement of the nozzle in the other plane, each actuatingram being arranged to be remotely controlled automatically by hydrauliccontrol apparatus comprising a first double-acting cylinder, referred toas a slave cylinder, which can be connected hydraulically for drivingthe actuating ram, a second double-acting ram, referred to as a mastercylinder, a mechanical connection between the piston of the slavecylinder and the piston of the master cylinder, the connection beingadapted to cause reciprocating movement of the slave pistoncorresponding to reciprocating movement of the master piston, apilot-operated hydraulic valve adapted to control the hydraulic pressuresupply to the master cylinder, the pilot-operated hydraulic valve beingarranged automatically to reverse the direction of movement of themaster ram, pilot means adapted to control the pilot-operated hydraulicvalve, and limit switch means adapted to actuate the pilot means andarranged for determining the desired length of stroke of the actuatingram.

4. A hydraulic monitor as claimed in claim 3, wherein the bore of eachslave cylinder is the same as the bore of the actuating ram associatedwith it.

5. A hydraulic monitor as claimed in claim 4, wherein the effectivestroke length of each slave cylinder is shorter than the effectivestroke length of the actuating cylinder associated with it.

6. A hydraulic monitor as claimed in claim 5, wherein the hydraulicmotor is a Pelton wheel.

7. A hydraulic monitor as claimed in claim 3, wherein the controlapparatus is hydraulically connected to each actuating ram by flexibleconduits including selfsealing releasable couplings.

1. A hydraulic monitor including a water jet nozzle mounted for pivotingmovement in at least one plane, the pivoting movement being effected bya hydraulic actuating ram which is arranged to be controlledautomatically by hydraulic control apparatus comprising a firstdouble-acting cylinder, referred to as a slave cylinder, which can beconnected hydraulically for driving the actuating ram, a seconddouble-acting ram, referred to as a master cylinder, a mechanicalconnection between the piston of the slave cylinder and the piston ofthe master cylinder, the connection being adapted to cause reciprocatingmovement of the slave piston corresponding to reciprocating movement ofthe master piston, a pilot-operated hydraulic valve adapted to controlthe hydraulic pressure supply to the master cylinder, the pilot-operatedhydraulic valve being arranged automatically to reverse the direction ofmovement of the master ram, pilot means adapted to control thepilot-operated hydraulic valve, and limit switch means adapted toactuate the pilot means and arranged for determining the desired lengthof stroke of the actuating ram.
 2. A hydraulic monitor as claimed inclaim 1, in which the hydraulic pressure for operating the mastercylinder is supplied by a pump adapted to be driven by a hydraulic motordriven by means of water pressure derived from the supply of water tothe nozzle of the monitor.
 3. A hydraulic monitor including a nozzlemounted for pivoting movement in two mutually perpendicular planes, afirst actuating ram for effecting movement of the nozzle in one planeand a second actuating ram for effecting movement of the nozzle in theother plane, each actuating ram being arranged to be remotely controlledautomatically by hydraulic control apparatus comprising a firstdouble-acting cylinder, referred to as a slave cylinder, which can beconnected hydraulically for driving the actuating ram, a seconddouble-acting ram, referred to as a master cylinder, a mechanicalconnection between the piston of the slave cylinDer and the piston ofthe master cylinder, the connection being adapted to cause reciprocatingmovement of the slave piston corresponding to reciprocating movement ofthe master piston, a pilot-operated hydraulic valve adapted to controlthe hydraulic pressure supply to the master cylinder, the pilot-operatedhydraulic valve being arranged automatically to reverse the direction ofmovement of the master ram, pilot means adapted to control thepilot-operated hydraulic valve, and limit switch means adapted toactuate the pilot means and arranged for determining the desired lengthof stroke of the actuating ram.
 4. A hydraulic monitor as claimed inclaim 3, wherein the bore of each slave cylinder is the same as the boreof the actuating ram associated with it.
 5. A hydraulic monitor asclaimed in claim 4, wherein the effective stroke length of each slavecylinder is shorter than the effective stroke length of the actuatingcylinder associated with it.
 6. A hydraulic monitor as claimed in claim5, wherein the hydraulic motor is a Pelton wheel.
 7. A hydraulic monitoras claimed in claim 3, wherein the control apparatus is hydraulicallyconnected to each actuating ram by flexible conduits includingself-sealing releasable couplings.